Depends what your business is. Brooklyn is full of Russians. San Francisco has Russians.
Brighton Beach, Brooklyn in NYC.
Wherever you prefer. Your nationality shouldn't be a factor.
Do you like your winters cold or warm?
Do you like your summers hot or hottest?
South Florida, I lived in Miami for almost a year and I noticed many Russians, especially near the Bal Harbour & Surfside areas. However be advised, there are many Latins and blacks that live in South Florida, it took me a while to get used to.